Another fill in foe, another script flipper, another contender for upset of the year. Danny Garcia knocked down Amir Khan three times and made the ref step in and halt the main event which unfolded at the Mandalay Bay in Las Vegas on Saturday night, and on HBO. Six to one underdog Garcia, channeling Josesito Lopez, another sub, who just upset Victor Ortiz, went ballistic after Kenny Bayless saw that Khan looked to shaky to continue in the fourth round.

The time of the finish was 2:28. “I'm a killer, baby,” Garcia said after. The first knockdown, off a left hook, was something he worked on in camp. The victor said he knew Khan would come out fast, and he planned to step it up after the third. Khan said he got caught by what looked like a blind shot but gave credit to the victor. Did he want to continue? He said he was OK, and in fact told the ref he was OK. “I was surprised the ref stopped the fight there,” he said. “I got up off the floor, I was fine…Maybe they made the right choice.”

The WBA junior welter champ Khan (lives in England; age 25; 26-1 with 18 KOs entering) was 139-148 pounds on fightnight, as was the WBC junior welterweight champion Garcia (from Philadelphia; age 24; 23-0 with 14 KOs entering), and 150 on fight night.

Some of the focus in the leadup to the fight was on the comments of Danny's dad, Angel, who said he never met a Pakistani who could fight. He got raked over the coals for a remark which he apparently just sees as nothing more than some unvarnished truth, that Pakistan doesn't have a rich history in the professional boxing sphere. Of course, the focus before that hubbub came when Khan's original foe, Lamont Peterson, got bumped from the gig, originally slated for May 19, because he tested positive for excess testosterone.

In the first, Khan came out smoking. His right hand was spot on, and Garcia ate a couple nasties, clean, to start. Khan was nailed in the groin but recovered quickly. We wondered if this would be an abbreviated contest.

In the second, Khan again stayed flat footed, didn't bounce or move nervously. His combos looked speedy as compared to Garcia's. A cut formed over the underdog's right eye in this round. Garcia had some luck himself, but his shots were a bit wide, and slower than Khan's. His dad-trainer called for left uppercuts and asked him to remain calm and work harder after the round.

In the third, Garcia looked to land to the body and wide rights to the ear area. He sent Khan down, on a counter left hook, to the neck, below the ear, with 18 seconds left. The punch looked like a “lucky” shot, some would say, but this is a young vet, and he shouldn't be dissed by calling that lucky. Khan made it to the end of the round, to his credit, because he was on shaky legs. Indeed, he was wobbling, and Kenny Bayless could easily have pulled the plug at that juncture. He had to fight the last nine seconds to get to the stool.

In the fourth, Khan went down again right away, as his knee touched the mat, from right hands. He then held on, and ran. “This fight is over, this fight is over,” said Jim Lampley at the 2:22 mark. Khan ate clean rights, then a left hook, and answered with a few hard shots.At 2:06, in fact, he waved Garcia toward him, inviting more slugging. Garcia threw a bit too wildly, maybe, but sent him down again, on his bum, with 45 seconds to go. That was a left hook to the top of the head. He got up, but the ref stopped it, not liking how Khan looked or responded after he asked him if he was OK. “You OK Amir?” Bayless asked, and Khan nodded, and hesitated before saying, “I'm OK.”

Is he? Folks will wonder now where Khan goes from here, if he can collect himself, if he will have to try and re-fashion his manner of fighting. He was stopped in round one against Breidis Prescott in 2008 and now this. Can he pull a Wladimir Klitschko, and re-start his career, with a greater focus on defense?

SPEEDBAG Max Kellerman taped the Sergio Martinez-Julio Cesar Chavez Jr. “Face Off” and he said the taping Thursday showed that both were confident. He called it a “tremendous matchup.”

—Soundman Paul Hoggatt, who worked more HBO boxing shows than anyone else, just passed away, and was lauded during the show and before the wrap, by a tearful Jim Lampley.